Hello Honors Physics students,

There are several options for turning in your work: Use a google doc, or share an email, or screen shot

your work on an ipad or photo on phone and share it with me at ted.grice@bvasd.net .

I will send out information on Remind or you can check school wires. Also check your school email from

time to time. To have continuity of learning here is a brief overview of the next 2 weeks

4/17 Go to https://www.physicsclassroom.com/class/momentum/Lesson-2/Momentum-Conservation-

Principle

4/20 Go to https://www.physicsclassroom.com/class/momentum/Lesson-2/Isolated-Systems

4/16 Test on momentum and impulse

4/17 Read lesson 2 on momentum conservation above and answer questions in tutorial

4/20 Read next lesson on isolated systems and answer questions in tutorial

4/21 Do worksheet on momentum basics See attached

4/22 Do momentum collisions applet based on yesterday See attached

4/23 Quiz on momentum conservation to date Hw crossword attached

4/24 Do simulation lab on collisions See attached worksheet

4/27 Do conservation of momentum worksheet 5.2 pages 57-61 attached

4/28 Do conservation of momentum worksheet 5.2 pages 62 -63 attached

4/29 Do physics classroom page 9-10 attached

4/30 Do physics classroom page 11-12 attached

Stay Safe!

Mr. Grice

Momentum conservation: Name:

Describe the following collisions or explosions in detail:

1. mavai + 0 = mava + mbvb

2. mavai + 0 = 0 + mbvb

3. mavai + mb(-vbi) = mava + mbvb

4. mavai + mb(-vbi) = ma(-va) + mb(-vb)

5. mavai + mb(-vbi ) = ma(-va) + mb(vb)

6. 0 = mava + mb(-vb)

7. (ma+mb)vi = ma(va) + mb(vb)

8. mavai + mb(-vbi) = (ma +mb) v

9. mavai + 0 = (ma +mb) v

1-5 describes an ________________________ collision

6-7 describes an ________________________

8-9 describes an ________________________ collision

Law of conservation of momentum states:

unless an _________________________

Try to do the following:

Match the equations from the sheet yesterday with the scenario needed in the applet to have the event

happen.

Notice: No collision is truly elastic.

See this video:

https://www.google.com/search?q=tennis+ball+hit+slow+motion&ie=utf-8&oe=utf-8&client=firefox-b-

1-ab

http://www.physicsclassroom.com/Physics-Interactives/Momentum-and-Collisions/Collision-

Carts/Collision-Carts-Interactive

Momentum/Collision Crossword PuzzleBy Andie Leeds and Nicole Johnson

Read each clue and fill in the appropriate answer in the corresponding space. Do NOT use spaces in your answer.

1

7

3

8

15

9

10 11

12

5

4

14

19

2

6

16 17

13

18

Across2 A collision when two objects collide and bounce apart.

3 When two balls hit in a game of pool, the momentum is ___________ between the two balls.

5 The SI unit for ________ is the kilogram*meter/second.

7 Circus safety nets, bungee jumping cords, and car airbags are all examples of ways to extend the ____ __ ______. (3 Words)

10 To ________ the force of impact, extend the time of impact.

12 To increase momentum, apply the ________ force possible for as long as possible.

13 _______ is indicated with the letter "J". 15 When an external force acts on an object.

17 The SI unit for _______ is the newton*second.

18 In a system where there are no outside forces, momentum before the collision is _______ to momentum after the collision.

19 When rollerskates are moving fast and a truck is moving slow, they have the same ________.

Down1 Change in velocity equals change in ____________.

4 Mass multiplied by velocity equals ________.

6 When an object bounces, impulses are _______.

8 Pulling a sling shot is and example of __________ momentum.

9 A collision when two objects stick together.

11 The law of conservation of momentum states that the total momentum in a system remains the same if no ________ forces act on the system.

13 The product of the force exerted on an object and the time interval during which it acts is called _______.

14 If a ping pong ball and a bowling ball are rolling down a hill with the same velocity, the bowling ball has more ________.

16 Force multiplied by time equals _______.

Collision Cart Lab Name ____________________________ Physics 1 2 3 4 5 6 7 8

www.simbucket.com -> Simulations -> Collision Cart Lab Perform the following collisions and record your results:

Before After

Elastic (Bounce)

Slow

v = ______m/s

Stopped

v = ______m/s

???

v = ______m/s

???

v = ______m/s

Change in Momentum

Left Cart

mleft = ________ kg

Momentum (P) = mass x velocity Pleft initial = __________!"#

!

Pleft final= __________!"#!

Pright initial = __________!"#!

Pright final = __________!"#!

∆𝑃 = 𝑃! − 𝑃!

ΔPleft = ______!"#!

Right Cart

mright = ________ kg ΔPright = ______!"#

!

Total

PTotal initial = __________!"#!

PTotal final = __________!"#!

ΔPTotal = ______!"#!

1. What was the change in momentum of the left cart? __________________ !"#

!

2. What was the change in momentum of the right cart? __________________ !"#

!

3. Was momentum conserved in this collision? How do you know?

Before After

Elastic (Bounce)

Slow

v = ______m/s

Fast

v = ______m/s

???

v = ______m/s

???

v = ______m/s

Change in Momentum

Left Cart

mleft = ________ kg

Momentum (P) = mass x velocity Pleft initial = __________!"#

!

Pleft final= __________!"#!

Pright initial = __________!"#!

Pright final = __________!"#!

∆𝑃 = 𝑃! − 𝑃!

ΔPleft = ______!"#!

Right Cart

mright = ________ kg ΔPright = ______!"#

!

Total

PTotal initial = __________!"#!

PTotal final = __________!"#!

ΔPTotal = ______!"#!

4. What was the change in momentum of the left cart? __________________ !"#

!

5. What was the change in momentum of the right cart? __________________ !"#

!

6. Was momentum conserved in this collision? How do you know?

Before After

Inelastic (Stick)

Fast

v = ______m/s

Medium

v = ______m/s

???

v = ______m/s

???

v = ______m/s

Change in Momentum

Left Cart

mleft = ________ kg

Momentum (P) = mass x velocity Pleft initial = __________!"#

!

Pleft final= __________!"#!

Pright initial = __________!"#!

Pright final = __________!"#!

∆𝑃 = 𝑃! − 𝑃!

ΔPleft = ______!"#!

Right Cart

mright = ________ kg ΔPright = ______!"#

!

Total

PTotal initial = __________!"#!

PTotal final = __________!"#!

ΔPTotal = ______!"#!

7. What was the change in momentum of the left cart? __________________ !"#

!

8. What was the change in momentum of the right cart? __________________ !"#

!

9. Was momentum conserved in this collision? How do you know?

Before After

Inelastic (Stick)

Stopped

v = ______m/s

Fast

v = ______m/s

???

v = ______m/s

???

v = ______m/s

Change in Momentum

Left Cart

mleft = ________ kg

Momentum (P) = mass x velocity Pleft initial = __________!"#

!

Pleft final= __________!"#!

Pright initial = __________!"#!

Pright final = __________!"#!

∆𝑃 = 𝑃! − 𝑃!

ΔPleft = ______!"#!

Right Cart

mright = ________ kg ΔPright = ______!"#

!

Total

PTotal initial = __________!"#!

PTotal final = __________!"#!

ΔPTotal = ______!"#!

10. What was the change in momentum of the left cart? __________________ !"#

!

11. What was the change in momentum of the right cart? __________________ !"#

!

12. Was momentum conserved in this collision? How do you know?

Before After

Explosion

Stopped

v = ______m/s

???

v = ______m/s

???

v = ______m/s

Change in Momentum

Left Cart

mleft = ________ kg

Momentum (P) = mass x velocity Pleft initial = __________!"#

!

Pleft final= __________!"#!

Pright initial = __________!"#!

Pright final = __________!"#!

∆𝑃 = 𝑃! − 𝑃!

ΔPleft = ______!"#!

Right Cart

mright = ________ kg ΔPright = ______!"#

!

Total

PTotal initial = __________!"#!

PTotal final = __________!"#!

ΔPTotal = ______!"#!

7. What was the change in momentum of the left cart? __________________ !"#

!

8. What was the change in momentum of the right cart? __________________ !"#

!

9. Was momentum conserved in this explosion? How do you know?

Before After

Moving Explosion

Slow

v = ______m/s

???

v = ______m/s

???

v = ______m/s

Change in Momentum

Left Cart

mleft = ________ kg

Momentum (P) = mass x velocity Pleft initial = __________!"#

!

Pleft final= __________!"#!

Pright initial = __________!"#!

Pright final = __________!"#!

∆𝑃 = 𝑃! − 𝑃!

ΔPleft = ______!"#!

Right Cart

mright = ________ kg ΔPright = ______!"#

!

Total

PTotal initial = __________!"#!

PTotal final = __________!"#!

ΔPTotal = ______!"#!

10. What was the change in momentum of the left cart? __________________ !"#

!

11. What was the change in momentum of the right cart? __________________ !"#

!

12. Was momentum conserved in this explosion? How do you know?

� �

5-2 Conservation of MomentumAccording to the law of conservation of momentum, the total momentum ina system remains the same if no external forces act on the system. Considerthe two types of collisions that can occur.

Vocabulary Elastic collision: A collision in which objects collide and bounce apart with noenergy loss.

In an elastic collision, because momentum is conserved, the mv before acollision for each of the two objects must equal the mv after the collision foreach of the two objects. This is written as

m1v1o � m2v2o � m1v1f � m2v2f

The subscripts 1 and 2 refer to objects 1 and 2, respectively.

Momentum 57

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Vocabulary Inelastic collision: A collision in which objects collide and some mechanicalenergy is transformed into heat energy.

A common kind of inelastic collision is one in which the colliding objects sticktogether, or start out stuck together and then separate. However, in an inelasticcollision the objects need not remain stuck together but may instead deform insome way.

Because momentum is also conserved in an inelastic collision, the mv beforethe collision for each of the two objects must equal the mv after the collisionfor each of the two objects. When objects are stuck together after the collision(assuming mass does not change), this equation becomes

m1v1o � m2v2o � (m1 � m2)vf

where vf is the combined final velocity of the two objects.

Solved Examples

Example 5: Tom and his twin brother Tim have a combined mass of 200.0 kg and arezooming along in a 100.0-kg amusement park bumper car at 10.0 m/s. They bump Melinda’s car, which is sitting still. Melinda has a mass of 25.0 kg.After the elastic collision, the twins continue ahead with a speed of 4.12 m/s.How fast is Melinda’s car bumped across the floor?

Solution: Notice that you must add the mass of the bumper car to the mass ofthe riders.

Given: m1 � 300.0 kg Unknown: v2f � ?m2 � 125.0 kg Original equation:v1o � 10.0 m/s m1v1o � m2v2o � m1v1f � m2v2fv2o � 0 m/sv1f � 4.12 m/s

Solve: v2f �

�

� �

� 14.1 m/s

1764 kg # m>s125.0 kg

3000 kg # m>s � 0 kg # m>s � 1236 kg # m>s125.0 kg

1300.0 kg 2 110.0 m>s 2 � 1125.0 kg 2 10 m>s 2 � 1300.0 kg 2 14.12 m>s 2

125.0 kg

m1v1o � m2v2o � m1v1fm2

58 Momentum

1220018-Ch05_053-064_TG 11/20/07 3:32 PM Page 58

Momentum 58

Example 6: Sometimes the curiosity factor at the scene of a car accident is so great that itactually produces secondary accidents as a result, while people watch to seewhat is going on. If an 800.-kg sports car slows to 13.0 m/s to check out anaccident scene and the 1200.-kg pick-up truck behind him continues travelingat 25.0 m/s, with what velocity will the two move if they lock bumpers after arear-end collision?

Solution: Since the two vehicles lock bumpers, both objects have the samefinal velocity.

Given: m1 � 800. kg Unknown: vf � ?m2 � 1200. kg Original equation:v1o � 13.0 m/s m1v1o � m2v2o � (m1 � m2)vfv2o � 25.0 m/s

Solve: vf � �

� � 20.2 m/s forward

Example 7: Charlotte, a 65.0-kg skin diver, shoots a 2.0-kg spear with a speed of 15 m/s ata fish who darts quickly away without getting hit. How fast does Charlottemove backwards when the spear is shot?

Solution: To start, Charlotte and the spear are together and both are at rest.

Given: m1 � 65.0 kg Unknown: v1f � ?m2 � 2.0 kg Original equation:vo � 0 m/s (m1 � m2)vo � m1v1f � m2v2fv2f � 15.0 m/s

Solve: v1f �

�

� � �0.46 m/s

Remember, the minus sign here is indicating direction. Therefore, Charlottewould travel with a speed of 0.46 m/s in a direction opposite to that of thespear.

�30.kg # m>s65.0 kg

165.0 kg � 2.0 kg 2 10 m>s 2 � 12.0 kg 2 115 m>s 2

65.0 kg

1m1 � m2 2vo � m2v2fm1

10,400 kg # m>s � 30,000 kg # m>s2000. kg

1800. kg 2 113.0 m>s 2 � 11200. kg 2 125.0 m>s 2

1800. kg � 1200. kg 2

m1v1o � m2v2o

1m1 � m2 2

Momentum 59

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Practice Exercises

Exercise 7: Jamal is at the state fair playing some of the games. At one booth, he throws a0.50-kg ball forward with a velocity of 21.0 m/s in order to hit a 0.20-kg bottlesitting on a shelf, and when he makes contact the bottle goes flying forward at30.0 m/s. a) What is the velocity of the ball after it hits the bottle? b) If thebottle were more massive, how would this affect the final velocity of the ball?

Answer: a.

Answer: b.

Exercise 8: Jeanne rolls a 7.0-kg bowling ball down the alley for the league championship.One pin is still standing, and Jeanne hits it head-on with a velocity of 9.0 m/s.The 2.0-kg pin acquires a forward velocity of 14.0 m/s. What is the newvelocity of the bowling ball?

Answer:

Exercise 9: Running at 2.0 m/s, Bruce, the 45.0-kg quarterback, collides with Biff, the90.0-kg tackle, who is traveling at 7.0 m/s in the other direction. Uponcollision, Biff continues to travel forward at 1.0 m/s. How fast is Bruceknocked backwards?

Answer:

60 Momentum

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Exercise 10: Anthony and Sissy are participating in the “Roll-a-Rama” rollerskating dancechampionship. While 75.0-kg Anthony rollerskates backwards at 3.0 m/s,60.0-kg Sissy jumps into his arms with a velocity of 5.0 m/s in the samedirection. a) How fast does the pair roll backwards together? b) If Anthony isskating toward Sissy when she jumps, would their combined final velocity belarger or smaller than your answer to part a? Why?

Answer: a.

Answer: b.

Exercise 11: To test the strength of a retainment wall designed to protect a nuclear reactor,a rocket-propelled F-4 Phantom jet aircraft was crashed head-on into aconcrete barrier at high speed in Sandia, New Mexico, on April 19, 1988. TheF-4 phantom had a mass of 19,100 kg, while the retainment wall’s mass was469,000 kg. The wall sat on a cushion of air that allowed it to move duringimpact. If the wall and F-4 moved together at 8.41 m/s during the collision,what was the speed of the F-4 Phantom upon impact?

Answer:

Momentum 61

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Exercise 12: Valentina, the Russian Cosmonaut, goes outside her ship for a spacewalk, butwhen she is floating 15 m from the ship, her tether catches on a sharp piece ofmetal and is severed. Valentina tosses her 2.0-kg camera away from thespaceship with a speed of 12 m/s. a) How fast will Valentina, whose mass isnow 68 kg, travel toward the spaceship? b) Assuming the spaceship remainsat rest with respect to Valentina, how long will it take her to reach the ship?

Answer: a.

Answer: b.

Exercise 13: A 620.-kg moose stands in the middle of the railroad tracks, frozen by thelights of an oncoming 10,000.-kg locomotive that is traveling at 10.0 m/s. Theengineer sees the moose but is unable to stop the train in time and the mooserides down the track sitting on the cowcatcher. What is the new combinedvelocity of the locomotive and the moose?

Answer:

Exercise 14: Lee is rolling along on her 4.0-kg skateboard with a constant speed of 3.0 m/swhen she jumps off the back and continues forward with a velocity of 2.0 m/srelative to the ground. This causes the skateboard to go flying forward with aspeed of 15.5 m/s relative to the ground. What is Lee’s mass?

Answer:

62 Momentum

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Additional Exercises

A-1: Bernie, whose mass is 70.0 kg, leaves a ski jump with a velocity of 21.0 m/s.What is Bernie’s momentum as he leaves the ski jump?

A-2: Ethel is sitting on a park bench feeding the pigeons when a child’s ball rollstoward her across the grass. Ethel returns the ball to the child by hitting itwith her 2.0-kg pocketbook with a speed of 20 m/s. If the impact lasts for 0.4 s, with what force does Ethel hit the ball?

A-3: When Reggie stepped up to the plate and hit a 0.150-kg fast ball traveling at 36.0 m/s, the impact caused the ball to leave his bat with a velocity of 45.0 m/s in the opposite direction. If the impact lasted for 0.002 s, what forcedid Reggie exert on the baseball?

A-4: The U.S. Army’s parachuting team, the Golden Knights, are on a routinejumping mission over a deserted beach. On a jump, a 65-kg Knight lands onthe beach with a speed of 4.0 m/s, making a 0.20-m deep indentation in thesand. With what average force did the parachuter hit the sand? (Read moreabout the Golden Knights at http://www.goldenknights.com)

A-5: The late news reports the story of a shooting in the city. Investigators thinkthat they have recovered the weapon and they run ballistics tests on the pistolat the firing range. If a 0.050-kg bullet were fired from the handgun with aspeed of 400 m/s and it traveled 0.080 m into the target before coming to rest,what force did the bullet exert on the target?

A-6: About 50,000 years ago, in an area located outside Flagstaff, Arizona, a giant4.5 � 107-kg meteor fell and struck Earth, leaving a 180-m-deep hole nowknown as Barringer crater. If the meteor was traveling at 20,000 m/s uponimpact, with what average force did the meteor hit the earth? (Read moreabout Barringer crater at http://www.barringercrater.com)

A-7: In November 2007, astronaut Pam Melroy, history’s second woman spaceshuttle commander, flew the space shuttle Discovery to the InternationalSpace Station to continue construction. To undock from the space station,Commander Melroy released hooks holding the two spacecraft together andthe 76,700 kg shuttle pushed away from the space station with the aid of 4 largesprings. a) If the 232,700 kg space station moved back at a speed of 0.50 m/s,how fast and in what direction did the space shuttle move? b) What is therelative speed of the two spacecraft as they separate? (Read more aboutastronaut Pam Melroy at http://www.jsc.nasa.gov/Bios/htmlbios/melroy.html)

A-8: Tyrrell throws his 0.20-kg football in the living room and knocks over hismother’s 0.80-kg antique vase. After the collision, the football bounces straightback with a speed of 3.9 m/s, while the vase is moving at 2.6 m/s in theopposite direction. a) How fast did Tyrrell throw the football? b) If the footballcontinued to travel at 3.9 m/s in the same direction it was thrown, would thevase have to be more or less massive than 0.80 kg?

Momentum 63

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A-9: A 300.-kg motorboat is turned off as it approaches a dock and it coasts intoward the dock at 0.50 m/s. Isaac, whose mass is 62.0 kg, jumps off the frontof the boat with a speed of 3.0 m/s relative to the boat. What is the velocity ofthe boat after Isaac jumps?

A-10: Miguel, the 72.0-kg bullfighter, runs toward an angry bull at a speed of 4.00 m/s. The 550.-kg bull charges toward Miguel at 12.0 m/s and Miguelmust jump on the bull’s back at the last minute to avoid being run over. Whatis the new velocity of Miguel and the bull as they move across the arena?

A-11: The U.S.S. Constitution, the oldest fully commissioned war ship in the world,is docked in Boston, Massachusetts. Also known as “Old Ironsides” for herseemingly impenetrable hull, the frigate houses 56 pieces of heavy artillery.Mounted on bearings that allow them to recoil at a speed of 1.30 m/s are 20 carronades, each with a mass of 1000. kg. If a carronade fires a 14.5-kgcannonball straight ahead, with what muzzle velocity does the cannonballleave the cannon? (Read more about the U.S.S. Constitution athttp://www.ussconstitution.navy.mil)

Challenge Exercises for Further Study

B-1: On a hot sumer afternoon, Keith and Nate are out fishing in their rowboatwhen they decide to jump into the water and go for a swim. Keith, whose massis 65.0 kg, jumps straight off the front of the boat with a speed of 2.00 m/srelative to the boat, while Nate propels his 68.0-kg body simultaneously off theback of the boat at 4.00 m/s relative to the boat. If the 100.-kg boat is initiallytraveling forward at 3.00 m/s, what is its velocity after both boys jump?

B-2: Lilly, whose mass is 45.0 kg, is ice skating with a constant speed of 7.00 m/swhen she hits a rough patch of ice with a coefficient of friction of 0.0800. Howlong will it take before Lilly coasts to a stop?

B-3: In a train yard, train cars are rolled down a long hill in order to link them upwith other cars as shown. A car of mass 4000. kg starts to roll from rest at thetop of a hill 5.0 m high, and inclined at an angle of 5.0° to the horizontal. Thecoefficient of rolling friction between the train and the track is 0.050. Whatvelocity would the car have if it linked up with 3 identical cars sitting on flatground at the bottom of the track? (Hint: The equation for rolling friction isjust like the one for sliding friction.)

64 Momentum

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